The present invention relates to a pivot system for pivotally connecting a movable component to a fixed component, more particularly such a system for pivotally connecting a movable thrust reverser element to an aircraft cowling.
Turbofan-type turbojet engines are well known in the art and typically comprise a fan located at the front of a turbojet engine, which fan directs a flow of bypass air through a duct bounded by an engine cowling on the inside and a fan cowling on the outside. The generally annular duct bounded by the engine cowling and the fan cowling may channel both the bypass flow and the primary exhaust flow at a downstream portion from the turbojet engine, or the duct may channel only the bypass flow.
In aircraft in which the engine is mounted outside of the airframe structure, the fan cowling and the engine cowling are configured to form boundaries of the bypass flow duct and to provide aerodynamic outer surfaces to reduce drag.
In all types of thrust reversers, a pivot attachment is utilized to pivotally attach the movable thrust reverser component, which may be a door, a cascade flap, a panel, or a rear baffle, to the fixed portion of the aircraft cowling to enable the thrust reverser component to move between forward and reverse thrust positions. FIG. 1 illustrates a known pivot attachment to pivotally connect the movable thrust reverer element 2, in this particular instance a thrust reverser door, to the fixed cowling structure 1. Pivots 2a comprise a shaft, a swivel assembly and a nut. Access hatches 20 and 21 are provided to facilitate access to the external portion of the shaft and to the nut to facilitate the installation of the pivot system. However, this known design incurs many drawbacks. It requires a large number of components, thereby increasing the manufacturing costs, and has several component interfaces which require adjustment and particular attention during the installation process and during later maintenance processes. The areas occupied by the access hatches 20 and 21 are not available for structural reinforcement or acoustic insulation of either the cowling or the thrust reverser door.